It’s not summer if the kids can’t have the occasional water fight, right? Let the kids haul out the squirt guns and go at it.
I don’t like having to constantly refill squirt guns, and my youngest can’t handle it herself from a faucet or hose yet, so I fill a 5 gallon bucket with water that she can dunk it into for refills. Saves me a lot of trouble. Just make sure that your child can safely deal with water in a bucket. Drowning can be a problem even with a bucket of water.